Laboratory Evaluation of Warm Stone Matrix Asphalt Mixture

2011 ◽  
Vol 243-249 ◽  
pp. 4178-4181 ◽  
Author(s):  
Shao Wen Du ◽  
Shan Shan Li

Two kinds of warm additives, Sasobit and Evotherm DAT, were used to develop warm stone mastic asphalt (SMA) mixture. The test results showed that compaction temperature of SMA can be decreased by 30-40°C when using Sasobit or Evotherm DAT. Then, to compare the mechanical performance properties of SMA and warm SMAs, mechanical properties of pavement mixture, including Marshall stability, retained Marshall stability, tensile strength ratio, Cantabro loss, rutting dynamic stability and low temperature flexural strength, were tested in laboratory. The results indicated that Sasobit can decrease obviously the moisture resistance ability and low temperature cracking resistance ability of SMA. Therefore, the pavement performance properties of Sasobit warm SMA are inferior to those of Evotherm DAT warm SMA, which has the nearly same performance properties as hot SMA.

2012 ◽  
Vol 178-181 ◽  
pp. 1369-1372 ◽  
Author(s):  
Shao Wen Du ◽  
Shan Shan Li

The effect of three types of warm additives, including Sasobit, Aspha-min and Evotherm DAT, on the compaction temperature, rutting resistance, low temperature resistance and moisture resistance of hot asphalt mixture (HMA) were evaluated by laboratory test. The test results show that Sasobit, Aspha-min and Evotherm DAT can reduce the compaction temperature of HMA by 27°C, 20°C and 30°C respectively. These warm additives all can improve obviously the rutting resistance of HMA. However, Evotherm DAT can increase low temperature cracking resistance ability of HMA. Aspha-min has obviously negative effect on the low temperature cracking resistance and moisture resistance of HMA. Therefore, it is necessary to investigate performance properties of HMA when selecting warm additives.


Author(s):  
Ekarizan Shaffie ◽  
◽  
H.A. Rashid ◽  
Fiona Shiong ◽  
Ahmad Kamil Arshad ◽  
...  

Stone Mastic Asphalt (SMA) is a gap-graded hot mixture designed to provide higher resistance towards permanent deformation and rutting potential by 30% to 40% more than dense-graded asphalt, due to its stable aggregate skeleton structure. However, compared to other types of hot mix asphalt, SMA unfortunately has some shortcomings in term of its susceptibility towards moisture-induced damage due to its structure and excessive bitumen content in the composition. This research aims to assess the performance of a SMA mixture with steel fiber by enhancing overall stability, abrasion resistance, and, most importantly, moisture susceptibility. This study involved the incorporation of various steel fiber proportions of 0%, 0.3%, 0.5% and 0.7% by the total weight of mixture. The steel fiber modified SMA was made up of 6.0% PEN 60/70 bitumen content. The performance of SMA were evaluated through Marshall stability and flow test, Cantabro loss test and indirect tensile strength test. The results obtained from the testing showed that the incorporation of steel fiber is significantly effective to enhance the resistance towards moisture damage, while increasing the stability and reducing the abrasion loss of SMA mixture, compared to conventional mixture. Overall, it can be concluded that the addition of steel fiber in asphalt mixture specifically SMA, has improved the mechanical performance in the application of asphalt pavement with the optimum steel fiber proportion of 0.3% by the weight of mixture. The developed models between the independent variables and responses demonstrated high levels of correlation. The study found that Response Surface Methodology (RSM) is an effective statistical method for providing an appropriate empirical model for relating parameters and predicting the optimum performance of an asphaltic mixture to reduce flexible pavement failure.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe

This study investigates the substitution of conventional aggregate with a Florida washed shell in open-graded asphalt mixtures and evaluates the optimal substitution percentage in aggregate gradations of various nominal maximum aggregate sizes (NMASs) (i.e., 4.75, 9.5, and 12.5 mm). Laboratory experiments were performed on open-graded asphalt mixture specimens with the coarse aggregate of sizes between 2.36 and 12.5 mm being replaced by the Florida washed shell at various percentages (0, 15, 30, 45, and 100%). Specimen properties relevant to the performance of open-graded asphalt mixtures in the field were tested, evaluated, and compared. Specifically, a Marshall stability test, Cantabro test, indirect tensile strength test, air void content test, and permeability test were conducted to evaluate the strength, resistance to raveling, cracking resistance, void content, and permeability of open-graded asphalt mixtures. The results show that there is no significant difference in the Marshall stability and indirect tensile strength when the coarse aggregates are replaced with Florida washed shell. This study also found that the optimum percentages of Florida washed shell in open-graded asphalt mixture were 15, 30, and 45% for 12.5, 9.5, and 4.75 mm NMAS gradations, respectively.


2010 ◽  
Vol 168-170 ◽  
pp. 1145-1148 ◽  
Author(s):  
Xin Qiu ◽  
Lan Yun Chen ◽  
Liang Xue

The paper investigates the effects of different concentrations of crumb rubber (CR) on the pavement performance of the conventional penetration-grade 80/100 bitumen and the dense-graded wearing course asphalt mixture (AC16). A wet process and 0.6mm size CR were used and the control variables included three types of CR of concentrations 5%,10% and 15% by total weight of binder. The evaluations were twofold. Firstly, a comparison of the basic and rheological properties of those modified and unmodified binders was conducted. Secondly, a comparison of the resistance to moisture damage, low temperature cracking and permanent deformation of the AC16 and CR modified AC16 was performed. The results show that all the CR modified binders and mixtures are found to have improved performance as evaluated by a series of laboratory tests. In addition, among three CR concentrations, AC16 modified with 10%CR by total weight of binder exhibits the most satisfactory performance properties with respect to the resistance to moisture damage, permanent deformation and low temperature cracking.


2014 ◽  
Vol 599 ◽  
pp. 110-114 ◽  
Author(s):  
Yan Hua Wang ◽  
Kuang Yi Liu ◽  
Hai Xia Zhang ◽  
Shan Li

Anti-rut agent, named RPS-3000,was added into AC-25 asphalt mixture and its effects on high temperature stability, low temperature cracking resistance, water damage resistance and fatigue life were investigated in this paper. Results showed that the high temperature stability and low temperature crack resistance of the asphalt mixture improved significantly, the water damage stability increase slightly due to the introduction of anti-rut agents. Besides, the result of fatigue life test presented that excess amount of anti-rut agent may lead a deterioration of fatigue life. Keywords: Anti-rut agent; High temperature stability; Asphalt mixture


2012 ◽  
Vol 557-559 ◽  
pp. 329-333
Author(s):  
Zhong Run Zheng ◽  
Chao Zhao ◽  
Yi Feng Zhao ◽  
Pei Song

This paper introduces an asphalt mixture that mixed with different admixtures, rutting resistance agent and lignin fiber, at the same time. Rutting test and freeze-thaw splitting test are used to analyze rutting resistance on the high temperature and low temperature cracking of the asphalt mixture. The experiments with different mixes material composition are conducted to analysis various properties of the two admixtures on the mixture, especially the high temperature stability, low temperature crack resistance and the law of improvement effect. In addition, the experiments also determine the optimal asphalt content of different type of mixtures. The results showed that the single-doped KTL rutting resistance or lignin fibers have some improvement in water temperature performance of asphalt mixture, stability improvement of double-doped admixture asphalt mixture is better than the single-doped asphalt mixture, such as KTL rutting resistance agents and lignin fibers


2013 ◽  
Vol 361-363 ◽  
pp. 1625-1628
Author(s):  
Zhao Sheng Li ◽  
Yi Qiu Tan

Establish the mechanical model of asphalt pavement low-temperature cracking, analysis the factors leading to cracking. The factors such as shrinkage coefficient of asphalt pavementtemperature stresspavement structure combination forms and temperature contribution affect the asphalt pavement on cracking behavior. Study the effect of aggregate gradation type on asphalt mixture temperature shrinkage coefficient, analyze shows that in case of the same skeleton type, the smaller the average particle size of aggregate is, the larger low-temperature shrinkage deformation of mixture is; increasing the amount of coarse aggregate can form the dense structure of skeletonreduce the shrinkage coefficient at low temperature and improve the low-temperature crack resistance ability of asphalt mixture.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Wenhui Zhao ◽  
Xiangbing Xie ◽  
Guanghui Li ◽  
Jiuguang Geng ◽  
Meng Bao ◽  
...  

To expand the application range of modified asphalt and mixtures and effectively reduce the aggregation of nanomaterials in asphalt, nanocarbon/styrene butadiene styrene (SBS)/rubber powder composite-modified asphalt is proposed. This paper presents a laboratory study on the performance of nanocarbon/copolymer SBS/rubber powder composite-modified asphalt, and nanocarbon particles modified by titanate coupling agents as modifiers are selected. The nanocarbon/copolymer SBS/rubber powder composite-modified asphalt was prepared by a high-speed shearing method. The physical properties and rheological performance were assessed using ductility tests, softening point tests, penetration tests, dynamic shear rheometer (DSR) tests, and bending beam rheometer (BBR) tests. Furthermore, the mixture properties, including the high-temperature stability, low-temperature cracking resistance, moisture stability, and freeze-thaw splitting, were evaluated in the laboratory. The micromorphology of the base asphalt and composite-modified asphalt was examined by scanning electron microscopy (SEM), and the reactions between the modifiers and AH-70 base asphalt were studied by Fourier transform infrared spectroscopy (FTIR). The results reveal that the surface-modified nanocarbon and rubber powder additives substantially increased the softening point and penetration index of the base asphalt, with little obvious influence on the low-temperature performance. In addition, when nanocarbon/copolymer SBS/rubber powder composite-modified asphalt was used, the high-temperature stability and low-temperature cracking resistance of the nanocarbon/copolymer SBS/rubber powder composite-modified asphalt mixture were approximately 1.3 times those of the nanocarbon/rubber powder asphalt mixture. In terms of the micromorphology and reaction, the addition of the nanocarbon can increase the compatibility between the base asphalt and rubber powder, and then the addition of copolymer SBS can improve the structure of nanocarbon (after surface modification)/rubber powder-modified asphalt to form a stable network. Moreover, the physical reaction plays the dominant role in the modification process for the rubber powder and base asphalt, and chemical reactions occur in the modification process for the surface-modified nanocarbon and base asphalt.


2014 ◽  
pp. 1841-1850
Author(s):  
Augusto Falchetto ◽  
Ki Moon ◽  
Mihai Marasteanu

2014 ◽  
Vol 587-589 ◽  
pp. 1332-1336
Author(s):  
Jun Qing Chen ◽  
Ai Jun Li ◽  
Mei Qian Jin ◽  
Min Nan Zheng ◽  
Wan Yi Yang

Prone to low temperature cracking of asphalt pavement problems in cold areas, testing BBR on 70# base asphalt and 4 kinds of different dosage of SBS modified asphalt, testing TSRST on their mixture to appraisal the low temperature performance of SBS modified asphalt mixture. Results show that compared with the temperature stress of internal cracks of base asphalt and SBS modified asphalt mixture not rise significantly. But the stress of SBS asphalt mixture growing slow and the temperature of cracking reduce obviously; it means the low temperature performance improved. This shows that SBS improves the toughness and reduced the modulus of asphalt mixture in low temperature, rather than increasing the tensile strength of mixture specimens.


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